Center for Translational Neuromedicine Newshttp://www.urmc.rochester.edu:443/ctn/news-events/news/
Center for Translational Neuromedicine NewsSun, 02 Aug 2015 12:11:55 -0400Study Sheds New Light on Brain's Source of Power http://www.urmc.rochester.edu:443/ctn/news-events/news/?display=2015#newsItem1360
New research published today in the journal Nature Communications represents a potentially fundamental shift in our understanding of how nerve cells in the brain generate the energy needed to function. The study shows neurons are more independent than previously believed and this research has implications for a range of neurological disorders.

These findings suggest that we need to rethink the way we look at brain metabolism, said Maiken Nedergaard, M.D., D.M.Sc., co-director of the University of Rochester Center for Translational Neuromedicine and lead author of the study. Neurons, and not the brain's support cells, are the primary consumers of glucose and this consumption appears to correlate with brain activity.

At upper left, a healthy astrocyte (a supportive brain cell) is shown in blue between green sheaths of myelin, which are produced by
oligodendrocytes, the tentacled objects also seen in green.In individuals suffering from Progressive multifocal leukoencephalopathy,
JC viruses (red particles) first infect the astrocyte (upper right) and mutate, eventually causing the astrocyte to explode (bottom image).
The viruses then infect the oligodendrocytes.

When University researchers Steven Goldman and Maiken Nedergaard created a mouse model whose brains consisted of both animal neurons and human glia cells, their study initially focused on findings that the human cells essentially made the mice smarter.

However, they also created a powerful new platform for researchers to study human glial cells in experimental animals. And that is providing new insights into Progressive multifocal leukoencephalopathy (PML).

The study, out today in the journal Cell Stem Cell, suggests that the evolution of a subset of glia called astrocytes - which are larger and more complex in humans than other species - may have been one of the key events that led to the higher cognitive functions that distinguish us from other species.

]]>Fri, 13 Feb 2015 00:00:00 -0400http://www.urmc.rochester.edu:443/ctn/news-events/news/?display=2015#newsItem1307Mice injected with human brain cells get smarter, scientists sayhttp://www.urmc.rochester.edu:443/ctn/news-events/news/?display=2014#newsItem1270
What would Stuart Little make of it? Mice have been created whose brains are half-human. As a result, the animals are smarter than their siblings. The idea is not to mimic fiction but to advance understanding of human brain diseases by studying them in whole mouse brains rather than in laboratory dishes.

The altered mice still have mouse neurons - the thinking cells that make up around half of all their brain cells. But practically all their glial cells, the ones that support the neurons, are human.

It's still a mouse brain, not a human brain, says Steve Goldman of the University of Rochester Medical Center in New York. But all the non-neuronal cells are human.

A new study out today in the Journal of Neuroscience shows that traumatic brain injury can disrupt the function of the brain's waste removal system. When this occurs, toxic proteins may accumulate in the brain, setting the stage for the onset of neurodegenerative diseases such as Alzheimer's and chronic traumatic encephalopathy.

We know that traumatic brain injury early in life is a risk factor for the early development of dementia in the decades that follow, said Maiken Nedergaard, M.D., D.M.Sc., co-director of the University of Rochester Center for Translational Neuromedicine and senior author of the article. This study shows that these injuries set into motion a cascading series of events that impair the brain's ability to clear waste, allowing proteins like tau to spread throughout the brain and eventually reach toxic levels.

The findings are the latest in a series of new insights that are fundamentally changing the way scientists understand neurological disorders. These discoveries are possible due to a study published in 2012 in which Nedergaard and her colleagues described a previously unknown system of waste removal that is unique to the brain which researchers have dubbed the glymphatic system.

Researchers have developed new insight into a rare but deadly brain infection, called progressive multifocal leukoencephalopathy (PML). This disease - which is caused by the JC virus - is most frequently found in people with suppressed immune systems and, until now, scientists have had no effective way to study it or test new treatments.

The JC virus is an example of an infection that specifically targets glia, the brain's support cells, said neurologist Steve Goldman, M.D., Ph.D., co-director of University of Rochester Center for Translational Neuromedicine and senior author of the paper. Because this virus only infects human glia and not brain cells in other species, it has eluded our efforts to better understand this disease. To get around this problem, we have developed a new mouse model that allows us to study human glia in live animals.

The new discovery - which appears today in the Journal of Clinical Investigation - was the result of research using a new tool developed at the University of Rochester. Last year, Goldman and Maiken Nedergaard, M.D., D.M.Sc., reported that they had created a mouse model whose brains consisted of both animal neurons and human glia cells. While the previous study focused on the fact that the human cells essentially made the mice smarter, at the same time it created a powerful new platform for researchers to study human glial cells in live adult animals, including diseases that impact these cells.